Archbishop Silvano Maria Tomasi told CNA that “the Holy See is working to create a public opinion convinced that the world is safer without nuclear weapons, rather than with them.”

The archbishop is delegate secretary to the Dicastery for Promoting Integral Human Development, which is working to organize the disarmament conference.

The Holy See has invited Antonio Gutierres, Secretary General of the United Nations, to address the conference. It is not reported whether he has accepted the invitation.

Archbishop Tomasi said that the conference is conceived as a follow-up to the Treaty on the Prohibition of Nuclear Weapons, passed July 7 at the United Nations.

Until the treaty, nuclear weapons were the only weapons of mass destruction not explicitly banned by any international document.

The treaty passed with 122 votes in favor and one abstention, Singapore. However, 69 countries, namely all nuclear weapons states and all NATO members excepting the Netherlands, did not take part in the vote.

The U.N. decided to start negotiations for the treaty after a series of three conferences on the humanitarian consequences of nuclear weapons. The first conference took place in Oslo, Norway in March 2013. The second was held in Nayarit, Mexico in February 2014.

The third conference, held in Vienna, Austria, Dec. 8-9, 2014, was the first meeting on nuclear weapons attended by some nuclear weapons states.

At the end of the Vienna conference, 127 states formally endorsed a humanitarian pledge, with 23 more voting to approve a resolution in its favor. The endorsing states said they were aware that the risk of nuclear weapons use and their “unacceptable consequences” are avoidable only “when all nuclear weapons have been eliminated.”

The pledge called on all nuclear powers to take concrete measures to reduce the operational status of nuclear weapons and remove them from deployment. It called on nuclear powers to diminish nuclear weapons’ role in their military doctrines and to make “rapid reductions of all types of nuclear weapons.”

Archbishop Tomasi, who attended the Vienna conference in his former position of Holy See Permanent Observer to the U.N. in Geneva, told CNA that the Vienna conference is “particularly important, because it underscores that just being in possession of nuclear weapons is already not ethical.”

The November 2017 conference at the Vatican aims to be another step on the path towards nuclear disarmament.

It would build on the conference to negotiate the Nuclear Weapons Ban Treaty, which took place in New York in March 2017.

Pope Francis sent a message to that conference saying that the doctrine of nuclear deterrence has become ineffective against 21st century threats like terrorism, asymmetrical conflicts, environmental problems and poverty.

These threats, the Pope stressed, are “even greater when we consider the catastrophic humanitarian and environmental consequences that would follow from any use of nuclear weapons, with devastating, indiscriminate and uncontainable effects, over time and space.”

To Pope Francis, the elimination of nuclear weapons is both “a challenge and a humanitarian imperative.” The Pope also asked attendees to promote “reflection on an ethics of peace and multilateral and cooperative security that goes beyond the fear and isolationism that prevail in many debates today.”

As a permanent observer to the United Nations, the Holy See took part in the negotiations. It was granted the possibility to participate at procedural votes during the negotiations, a right that the Holy See usually does not use.

The Holy See is a founder and member state of the International Atomic Energy Agency (IAEA), and has always praised the developments in nuclear technology while strongly opposing the development of such technology for military purposes.

This was evident in the May 3 remarks of Monsignor Janusz Urbanczyk, the Holy See’s representative to the IAEA.

Addressing the first meeting for the 2020 review conference of the Treaty on the Non-proliferation of Nuclear Weapons, he stressed that “the Holy See cannot but lament the fact that the potential devastation caused by the use of nuclear weapons so clearly identified over 40 years ago has not been relegated to history.”